Clinical Comparison of OC-Sensor Pledia and Phadia 250 for Fecal Calprotectin Testing

Background: The fecal calprotectin (f-Cal) test is a convenient method used for differentiating inflammatory bowel disease (IBD) from functional bowel disorders. The OC-Sensor Pledia (OC-FCa; Eiken Chemical Co., Tokyo, Japan) is a latex agglutination turbidimetric immunoassay used for f-Cal measurements. We evaluated the clinical performance of OC-FCa and compared the f-Cal levels between OC-FCa and Phadia 250 (Thermo Fisher Scientific, Freiburg, Germany). Methods: We collected 278 stool samples; of these, 158 were taken from patients with suspected IBD, and 120 were taken from healthy individuals. We analyzed the f-Cal distribution in each group and compared the clinical performance and agreement between OC-FCa and Phadia 250. Results: The f-Cal of patients with IBD was significantly different from that of patients without IBD for both OC-FCa and Phadia 250 (p < 0.0001 and p < 0.001, respectively). The concordance between OC-FCa and Phadia 250 was 82.3%, with moderate agreement (kappa = 0.644, 95% confidence interval = 0.525-0.763). OC-FCa and Phadia 250 showed a high correlation (r = 0.90); their diagnostic performance showed moderate accuracy (AUC = 0.873 and 0.866, respectively) and had no significant difference (p = 0.616). Conclusions: Both OC-FCa and Phadia 250 showed a high correlation and good clinical performance. F-Cal measured using OC-FCa was reliable for initial differentiation between patients with IBD and without IBD. Therefore, OC-FCa and Phadia 250 could be alternative devices for measuring f-Cal depending on the laboratory situation.